Most articles that are commercially shipped are placed within corregated cardboard containers, hereinafter referred to as cartons. The carton filled with the articles to be contained are sealed by application of adhesive to appropriate carton components. The application of the adhesive to the carton components must be controlled since the adhesive should not be applied to any of the articles within the carton. If adhesive is applied to the carton contents, the subsequent opening of the carton will damage the articles therein.
Furthermore, if the articles within the carton are affixed to one another as well as to the carton, the articles may be removed from the carton while affixed without noticing the condition. If the articles are then placed in a location to be dispensed and sold then the affixed condition of the articles can cause problems with the sale of the articles.
Further compounding the problem is the fact that after the carton has been sealed, there is no practical means for detecting whether or not the articles within the carton have mistakenly received adhesive. The problem is discovered only after the carton has left the control of those who could alleviate the problem by repacking the articles in another carton and applying the adhesive properly. The purchasers who discover the defect have no means to correct the defect other than return the carton and its contents. The return of such materials is a waste of effort by the purchaser and those responsible for repacking the cartons.
This has created a longstanding search for a means to apply adhesive only to predetermined portions of cartons.
U.S. Pat. No. 3,769,777 Miller et al., discloses a case sealer that applies adhesive only to the end flaps of a carton. The application of the adhesive is controlled by four switches, two of which contact the carton and two of which contact a portion of the carton manipulating apparatus termed the flight bar. The switches taught are conventional electrical micro-switches requiring physical contact with the apparatus or the carton to make or break the electrical circuit.
Similarly, U.S. Pat. No. 3,496,697 Loveland et al., teaches an apparatus for applying adhesive to a carton prior to a closing operation. The application of adhesive is controlled by a linear array of four conventional electrical switches disposed along the direction of movement of the carton through the apparatus. The necessity of four switches in this reference as well as the previously cited reference increases the probability of malfunction since the switches are repetitively used. Furthermore, the failure of one particular switch in the array can result in the application of adhesive to the contents of the carton as well as both the end flaps.
By contrast, any probable combination of failure of either of the two switches of the present invention causes easily detectable incomplete misapplications of the adhesive, which cannot result in complete sealing of the carton with adhesive applied to its contents. Therefore, if the carton is completely sealed, those packing the carton and the purchasers of the articles within it can be assured that the contents of the cartons are not affixed to the carton itself. Furthermore, if a switch failure causes adhesive to be applied to the carton's contents, the carton will be incompletely sealed and easily detected. The improperly sealed cartons resulting from malfunction of the present invention visually appeared sealed, however, since one end is unsealed, it is structurally weaker than a correctly sealed carton and human handling of the carton will normally result in its detection. Furthermore, if after the apparatus has been utilized, it is discovered the cartons are improperly sealed, previously sealed cartons can externally be inspected to detect the improper application of adhesive. The external inspection consists simply of determining if either extremities of the external side flaps are not affixed to the end flaps. By contrast, the prior art devices create improperly sealed cartons that are externally indistinguishable from properly sealed cartons.
Therefore, it is a primary object of the invention to provide a more reliable apparatus for interacting with articles passing therethrough.
Another object of the invention, when the invention is embodied is an apparatus for applying adhesive to cartons, is to provide an apparatus that cannot completely seal a carton and apply adhesive to its contents upon the failure of the switch elements.
Still another object of the invention is to seal cartons in such a manner that malfunction of the apparatus will result in mis-sealed cartons that are externally detectable by unskilled personnel.
An additional object of the invention is to provide an apparatus that is easily adapted to various size articles passed therethrough.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.